1. Field of the Invention
The present invention relates to a process for the production of metallic formed members which include discrete particles embedded in a metallic matrix.
2. Description of the Prior Art
From the disclosure in German Patent Specification No. 24 60 013 there has become known a process for the production of formed or molded members which include discrete particles embedded in a metallic matrix. These particles are fastened to a metallic support and enveloped by a matrix which is constituted of a metallic powder. The support or carrier is isostatically pressed together with the particles and the enveloping material and thereafter sintered. The fragmentation bodies for projectiles which are produced pursuant to this process evidence a good fragmentation effect. However, the production of this fragmentation casing is complex from an economic standpoint since after the sintering, there will frequently be present unevenesses to the extent of a number of millimeters in the outer casing, which must be removed through a turning or machining operation. In order to be able to maintain the contemplated caliber size, the rough outer diameter of the fragmentation shell must, as a result, be selected of a relatively large size so as to be able to obviate that type of drawback. The extent of the machining on the fragmentation casing is thus relatively high. In addition thereto, the desired fragmentation effect cannot be reproduced in each instance since the matrix is forced at different depths into the interspaces between the particles during the pressing operation.
It is also disadvantageous that the sintering operation can adversely influence the metallurgical properties of the employed materials, such as the hardness or ductility. Moreover, the mentioned thermal process limits the number of materials which can be considered for the discrete particles.
Furthermore, from German Patent Specification No. 21 29 196 there has also become known a fragmentation body for fragmentation projectiles. Spherical fragments are filled in between two tubular members which are arranged within each other. Through high-pressure forming of the inner tubular member, the latter is pressed into the hollow interspaces between the fragments. Consequently, the tubular members are prefragmented and sandwiched together with the fragments into a fragmentation casing or shell. The high-pressure forming can be carried out in a shock-like manner, for example, through explosive shaping or electromagnetically, or also through pressing by means of a calibrating bolt.
A forming operation of that type is subject to the drawback in that, due to the degree of deformation which extends over too large a rolling width, the fragmentation effect is not reproducible to the required measure in that, because of the deformation force which cannot be uniformly distributed over the fragmentation casing, there will occur extremely high specific surface pressures which will fracture the spheres constituted, for instance, of hardened steel, such as ball bearing steel, and which will cause the deformation of the material of the inner casing beyond its ultimate tensile limits so as to cause a previously unpredictable reduction in the tensile strength. This reduction will also adversely affect the fragmentation effect.